1221504404 has 12 divisors (see below), whose sum is σ = 2138671584. Its totient is φ = 610455384.

The previous prime is 1221504379. The next prime is 1221504491. The reversal of 1221504404 is 4044051221.

It is a self number, because there is not a number n which added to its sum of digits gives 1221504404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64814 + ... + 81509.

It is an arithmetic number, because the mean of its divisors is an integer number (178222632).

Almost surely, 2^1221504404 is an apocalyptic number.

It is an amenable number.

1221504404 is a deficient number, since it is larger than the sum of its proper divisors (917167180).

1221504404 is a wasteful number, since it uses less digits than its factorization.

1221504404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148414 (or 148412 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 1221504404 is about 34950.0272389021. The cubic root of 1221504404 is about 1068.9687575004.

Adding to 1221504404 its reverse (4044051221), we get a palindrome (5265555625).

The spelling of 1221504404 in words is "one billion, two hundred twenty-one million, five hundred four thousand, four hundred four".